Even though Chris Columbus’ new film “Pixels” co-stars video game icons such as Donkey Kong, Pac-Man and Q*bert, the San Francisco director is particularly proud of the big-budget action-comedy’s practical effects.

“It wasn’t all CGI,” Columbus says. “We built the entire Donkey Kong set. Sometimes the actors were hundreds of feet in the air on harnesses, jumping over imaginary barrels.”

Columbus subjected Adam Sandler, Michelle Monaghan and Kevin James to the “grueling” harness treatment. In the film, Sandler’s character, a former video game prodigy, and fellow childhood champs Josh Gad and Peter Dinklage are assembled to fight space invaders who have taken the form of, well, Space Invaders and other 8-bit game characters. The trio is joined by a brainy lieutenant colonel played by Monaghan and the president, played rather incongruously by James.

“I kind of related to all of them,” Columbus says about the characters played by Sandler, Gad and Dinklage, who go from 1980s video game glory to dead-end jobs, conspiracy theories and prison, respectively, before getting a chance to save the world. “I could see in my life that I was really only good at one thing. And if for some reason the movie business kind of fell apart, I would be out of a job.

“My parents were both factory workers,” says Columbus, whose credits include directing “Home Alone” and “Harry Potter and the Sorcerer’s Stone,” as well as penning 1980s classics such as “The Goonies” and “Gremlins.” “I went to NYU film school, and I knew if I did not succeed I’d be working in a factory.”

The melancholy slant of Sandler’s character is something of a departure for the comedian, whose recent filmography includes broad comedies like 2011’s “Jack & Jill,” for which he became the first person to win both worst actor and worst actress at the Golden Raspberry Awards.

“Adam is a really good actor in films like ‘Punch Drunk Love’ and ‘Funny People,’” Columbus says, adding that the film’s emotional stakes “sort of upped the ante for everyone.”

“Pixels” was inspired by French director Patrick Jean’s 2010 short of the same name, in which characters made of “voxels” — the 3-D version of flat-screen pixels — terrorize a city. The 2015 film’s upgraded special effects included giving the game characters an arcade-bright inner glow.

“Doing this film was partially a course in physics for me,” Columbus says. “Voxelization is not something that was in my vocabulary a year and a half ago.”

So did producers ever consider naming the movie, which is screening in 3-D, “Voxels”?